- Radiographs:
- AP view:
- patella may be difficult to see on AP view;
- peripheral fractures (osteochondral frx) may be confused w/ bipartite patella;
- radiographs of contralateral knee can help in this differentiation because bipartite patella rarely occurs unilaterally;
- lateral view:
- best reveals the comminution of frx or separation of fragments;
- w/ separation of the fracture more than 3-4 mm may is usually associated w/ retinacular disruption and loss of active extension;
- w/ patellar comminution at the inferior pole, consider partial patellectomy;
- some vertical frxs are best seen on tangential or Merchant radiographs;
- CT or other advanced imaging techniques are usually unnecessary;
- bone scans have been used to help to identify stress fractures;

- Non Operative Rx:- indications:
- for undisplaced frxs w/ intact articular surface;
- preserved extensor mechanism w/ maintained active extension against gravity;
- retinacula on either side of patella should not be torn, as evidenced by pt's ability to maintain knee extended against gravity;
- there should be minimal displacement of fragments (2-3 mm)
- minimal disruption of the articular surface (2-3 mm)
- transverse undisplaced fracture of the patella is an avulsion frx;
- should aspirate with occurrence of tense hemotoma;